The Transmission Control Protocol (TCP) has been very successful and significantly contributes to the popularity of the Internet. See, for example, M. Allman et al., “TCP Congestion Control,” Request for Comments 5681 (RFC5681) (September 2009). A majority of Internet communications are transmitted using TCP. Recently, however, with the rapid advance of optical networks and rich Internet applications, TCP has been found to be less efficient as the network bandwidth-delay product (BDP) increases. Bandwidth-delay product refers to the product of the capacity of a data link (typically, in bits per second) and its round-trip delay time (typically, in seconds). BDP represents an amount of data measured in bits (or bytes) that is equivalent to the maximum amount of data on the network circuit at any given time (e.g., data that has been transmitted but not yet acknowledged).
The Additive Increase Multiplicative Decrease (AIMD) algorithm of TCP reduces the TCP congestion window significantly but fails to recover to the available bandwidth quickly. See, for example, D. Chiu, and R. Jain, “Analysis of the Increase/Decrease Algorithms for Congestion Avoidance in Computer Networks”, ISDN Systems, Vol. 17, No. 1, 1-14 (June 1989). Theoretical flow level analysis has shown that TCP becomes more vulnerable to packet loss as the BDP increases. See, for example, T. V. Lakshman and U. Madhow, “The Performance of TCP/IP for Networks with High Bandwidth-Delay Products and Random Loss,” IEEE ACM Trans. on Networking, Vol. 5 No 3, 336-50 (July 1997).
A need therefore exists for improved techniques for overcoming the inefficiency problem of TCP over high-speed wide area networks.